Monthly Maintenance: Randomly inspect fiber optic cable connections, test backbone fiber optic link attenuation, and clean connector end faces. Fiber cable quality is evaluated across multiple dimensions: Each parameter requires a specific test method and acceptance threshold. Visual. Some people have suggested that fiber optic networks need periodic maintenance, including microscopic inspection of connectors and mating adapters and even insertion loss testing or taking OTDR traces. This is the latest revision of a Recommendation that was first published in 1996. This revision is intended to be appropriate for the current situation with respect to. There are three main principles that needs to be taken in consideration for an efficient optical connection: a perfect core alignment, perfect physical contact and dirt-free connectors.